Ok, so we start again with a selection plan that shows a LEVEL STAKES PROFIT, a different proposition of course. A heap of staking plans here would increase the margin no doubt, but I would like to offer the folowing idea:
As we all know it's the losing run that kills us all off, so as a means of "spreading the risk" I've been working on an idea to treat say a whole meetings selections as one be OR (and this would suit your plan of more than one sel. per race Ubetido)
The possibilities are endless but one way would be calculate say three runners in a race as one bet i.e. split the stake (whatever it is) into 3 level bets, so for instance say the bet on that race is $30, so $10 win on each, say we have a 5/1 winner, so the return is $60, so we calc. this as an 1/1 winner, i.e $30 out $60 in.

Another way would be to count the entire meetings bets as 1 bet, i.e. say you have a selection method that selects 3 horse per race x 8 races, so 24 individual bets, lets say your staking plan calls for a bet of $72, so your stake is $3 win on each. say you have several winners and your return is $108 (to make the maths easy) so that is equivolent (overall) to a 1-2 winner, i.e. $72 out $108 in, etc etc.

As you can see there is many possibilities here but basically the idea is to avoid the dreaded losing run. Comments appreciated.